CXCR4 and plasma cell myeloma: The first use of cyclic pentapeptide, 68Ga-Pentixafor for CXCR4 PET imaging and its therapeutic analog 177Lu-Pentixather, in a patient with multiple myeloma showed high tumour-to-kidney and tumour-to-liver uptake ratios of 3.1 and 6.4 [65].